Question: Simplify the following expression: ${-10(-2z-4)-9(2+6z)}$
Solution: Distribute the ${-10}$ into the first set of parentheses: $ {-10(}\gray{-2z-4}{)} - 9(2+6z) $ $ {20z+40} - 9(2+6z) $ Distribute the ${-9}$ into the parentheses: $ 20z+40 {-9(}\gray{2+6z}{)} $ $ 20z+40 {-18-54z} $ Rewrite the expression to group the ${z}$ terms and numeric terms: $ {20z - 54z} + {40 - 18}$ Combine the ${z}$ terms: $ {-34z} + {40 - 18}$ Combine the numeric terms: $ {-34z} + {22}$ The simplified expression is $-34z+22$